<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>cartesianProduct</title>
</head>

<body>
    <div>打开浏览器控制台查看结果</div>
    <script>
        const cartesianProduct = (a, b) =>
            a.reduce((p, x) => [...p, ...b.map(y => [x, y])], []);
        console.log(cartesianProduct(['x', 'y'], [1, 2]));
    </script>
</body>

</html>